THE GREAT PONY HASSLE

Double trouble in a lightweight horse-story: When the mother of ten-year-old twins Staci and Toni marries the father of ten- year-old twins Stirling and Paisley, conflict is inevitable. Most outspoken of the four, Paisley insists on having a pony of her own; her father, caught in a weak moment, agrees. While he's honeymooning, Paisley finds the horse of her dreams; unfortunately, it's also the horse of Staci's dreams, causing much anguish and envy. While Staci fumes, Paisley prepares for the pony's arrival, finding an ally in Toni, who braves heat and hungry chiggers to help ready the back yard for ``Noodles.'' Springer delineates her characters well; seen from Staci's point of view, the grumpy, sweaty pettiness of the horse-less girls permeates the prose. Though the resolution is too good to be true (all four girls get horses), and the real issues of blending families are barely explored, young horse-story lovers will hop on eagerly for a quick ride. (Fiction. 7-11)